White Sox catcher Welington Castillo was recalled after serving an 80-game suspension for using a performance-enhancing substance.
Improved science could be a reason behind baseball's increase in positive drug tests.
Four Russian gold-medal winners at the Sochi Olympics used performance-enhancing drugs, according to whistleblowers who spoke with CBS' "60 Minutes" in an interview to air Sunday.
MLB is expected to announce in the next few days that another player has tested positive for the steroid Turinabol, which was common in the 1970s, a source told Outside the Lines.
Dodgers right-hander Josh Ravin has been suspended 80 games following a positive PED test.
